Several ophthalmic surgeries and procedures require dilation of the pupil to enable adequate viewing of the interior of the eye, and in particular the posterior chamber and posterior segment portions of the eye. For example, adequate dilation of the eye is generally essential during cataract and posterior segment surgery. Pupil dilation may also be required to extract foreign bodies lodged behind the iris.
In some instances, a patient's pupil may resist dilation efforts. For example, past surgery, recent trauma, and exfoliation syndrome may prevent the pupil from dilating adequately.
Various approaches have been taken to obtain and/or enhance pupil dilation. Some approaches are principally pharmacological, while other approaches involve surgery (i.e., ocular incisions) or mechanical manipulation of the iris. Pharmaceutical approaches are generally less preferred because, in a significant number of patients, the pharmaceuticals do not effectively dilate the pupil. Surgical approaches, including sphincterotomies and sector iridectomies, are also generally disfavored because of the possibility of surgical complications and cosmetic consequences. Another surgical approach uses sutures to tack the retracted iris through the scleral wall, but this approach requires delicate surgery and is time consuming. A hybrid surgical-mechanical approach involves the use of intraocular tacks that tack the iris to the sclera in a retracted position, but this approach requires the insertion of a surgical instrument behind the iris without adequate visualization, and may lead to inadvertent puncture of the iris and release of pigment into the eye. A mechanical approach for dilating or expanding the pupil includes pulling back the iris with translimbal iris hooks, which may cause damage to the iris tissue. Moreover, both the intraocular tacks and the iris hooks occasionally shift or slip from place, which can cause substantial complications during an ophthalmic surgery or other procedure.
The devices, systems, and methods disclosed herein overcome one or more of the deficiencies of the prior art.